The 2026-10-12 OOM killed the host, not the service: sowerd had no memory
ceiling anywhere while the sower client has had SOWER_MEMORY_LIMIT_MB since
d0031e4. Put a GOMEMLIMIT on the unit the installer writes and on the
packaged unit, so a runaway heap degrades sowerd instead of OOM-killing the
machine it runs on. kr already carries the same value through a drop-in.
sowerd was OOM-killed on kr with 970 MiB anon-rss on a 1.6 GiB host: a
connection burst in one window ballooned the heap and never came back.
Three unbounded holds made that possible, all on paths the log does not
show:
- the :80 listener had no timeouts, so a connection that never finished a
request kept a goroutine, a socket and its buffers for as long as the
peer stayed connected;
- the :443 accept loop had no concurrency cap, so resident memory grew with
the arrival rate (a failed handshake returns silently);
- relay.Relay only arms read deadlines, so a peer that stopped reading
blocked its writer forever, leaking the connection pair, its goroutines
and its descriptors (and the relay conn log never fired, because the call
never returned).
Arm a write deadline per write below the TLS listener, cap served
connections, set every plain-HTTP timeout, and dump a heap profile on
SIGUSR1 so the next occurrence can be attributed to an allocation site.
Evidence and the open questions (the trigger is still unproven, and r6c's
sower client shows a different, fd-independent growth) are recorded in
docs/plans/2026-10-12-sowerd-connection-bounds.md.
512515d renamed "## 实现决策" to "## 已推翻的实现决策" and kept the
struck-through upgrade claim, but the other two decisions were merged into one
line that stayed under the renamed header although neither was overturned.
Both halves of that line — the outbound Host rewrite, and the four reverse
proxy timeouts — were already stated in ARCHITECTURE.md at the time of that
trim (lines 143 and 146), and this plan's own scope line defers runtime facts
to the code and ARCHITECTURE.md. So the bullet was a duplicate as well as a
misfiling: drop it rather than move it, which also retires the forward note
dab041b had added to patch the stale claim.
The surviving bullet's evidence still exists: TestReverseProxyConnWebSocket and
TestReverseProxyConnPathRoutedWebSocket, cmd/sowerd/main_test.go:777 and :709.
Second half of the review: the rationale for `authority` had been written into
every comment that touched it, which is three copies to keep in sync. Keep the
argument in docs/security.md and leave the config example, the struct comment
and the constants stating only what the value does.
- docs/security.md: record "an upstream trusting X-Forwarded-Host" under
Rejected Directions, where the document already collects declined designs,
instead of inside the new rule section; merge the per-route bullet into the
client-controlled one they overlapped with.
- ARCHITECTURE.md: the sentence added last commit left the fake-site rationale
dangling after the site-route clause; split it back into one claim per
sentence.
- docs/plans/site-routing.md: the plan states the unconditional Host rewrite as
a decision of its time, so it gets a forward note to the authoritative
document rather than a rewrite of the record.
- config/sowerd.go: clearer validation error ("unknown value", naming both
accepted values) and a tighter comment; no behavior change beyond the
message.
The rewrite kept the pre-rewrite claim that leaving site_routes unset restores
the old behaviour exactly. It does not: the HTTP-looking fallback is
reverse-proxied with the original Host and edge forwarding headers
(ARCHITECTURE.md, sowerd Data Flow steps 13-14) and NextProtos is http/1.1-only,
which this same file already calls a deliberate decision. Say only what holds:
fake_site stays the single fallback target.
admin-console.md and site-routing.md still carried the full design and
implementation checklists for work that shipped and was written back to
ARCHITECTURE.md. Keep only what cannot be recovered from the code -- the two
frontend constraints and the site-routing trade-offs -- and point at the
authoritative documents. Drop the plan-to-plan "Supersedes" reference from
admin-persistence-config.md so plans stop sourcing rules from other plans.
security.md gains the rejected directions those rewrites now point at:
wildcard site_routes domains (rejected in validateSiteRoutes, and the SNI
dispatch is an exact-match siteRouter.lookup), additional listen addresses or
configurable 80/443 ports, per-site certificate binding, and domain routing on
plain HTTP.
Review of the anti-probing hardening found no code defects; the fixes
are documentation:
- docs/security.md: authoritative threat model, the three camouflage
layers, unknown-SNI certificate fallback rules (whitelist source,
error surfacing, capability propagation, concrete first entry), the
client_hello fingerprint knob, rejected directions (QUIC, h2) with
evidence, and residual accepted signals.
- Promote the plan doc to a non-authoritative historical record per
AGENTS.md docs rules; index security.md from docs/README.md and
ARCHITECTURE.md.
- config/sowerd.toml: document cert.domains; the first entry answers
unknown-SNI handshakes.
A handshake failure on unknown SNI is an active-probing signal: real
sites present their default vhost certificate. Whitelisted names keep
the plain autocert path with errors surfaced as-is; unknown or empty
SNI falls back to the primary domain's certificate, carrying the
client hello over so autocert derives the same ECDSA/RSA cache key.
The h2-on-fallback companion idea was investigated and rejected:
httputil.ReverseProxy has no RFC 8441 support and x/net gates
extended CONNECT behind GODEBUG only, which would break WingGate WSS.
ARCHITECTURE.md and README.md now describe editable config fields,
in-place restart, rule hit/miss stats, and session persistence; the
admin console plan is marked implemented.
- StateStore persists rule deltas and whitelisted config overrides atomically
- Config display/edit API with optimistic concurrency (revision)
- Traffic charts with time-axis linking across all views
- Split server.go into auth/rules/traffic/config by responsibility
- internal/admin: session-cookie auth server, rule CRUD API, bounded
per-domain traffic stats with pre-parse byte accounting
- cmd/sower: wrap proxied connections and DNS queries into stats, serve the
admin console on its own listener
- web/: Svelte 5 + Vite admin console with shadcn-svelte UI and an advanced
breadcrumb header (section/context dropdowns, favorites), embedded via
go:embed and committed to web/dist
- Makefile: sower build depends on the frontend build (bun); sowerd does not
- docs: ARCHITECTURE, README, and plan updated for the admin surface
wweir